Machine-translated by Google. Questions are authored in English.
Top

IP Routing Questions and Answers

11.

In hierarchical routing with 4800 routers, what region and cluster sizes should be chosen to minimize the size of the routing table for a threelayer hierarchy ?

Exam Year(s)

UGC NET - 2013,

Answer: D

For three level hierarchical routing the routing table has one entry for each cluster, one for each region of the local cluster and one for each router of the local region, so its size is the sum of the three numbers, while their product must equal the 4800 routers. Option (A) 10 x 24 x 20 = 4800 gives a table of 54, option (B) 12 x 20 x 20 = 4800 gives 52, option (C) 16 x 12 x 25 = 4800 gives 53, and option (D) 15 x 16 x 20 = 4800 gives 51. All four have the right product, and the smallest sum is 51 for 15 clusters, 16 regions and 20 routers, option (D). The sum is smallest when the three factors are as nearly equal as possible, near the cube root of 4800 which is about 16.9.

Please log in or register to report this question.

Discuss in Forum
12.

The count-to-infinity problem is associated with

Exam Year(s)

UGC NET - 2013,

Answer: C

The count-to-infinity problem is associated with the distance vector routing algorithm. When a link fails, routers keep exchanging increasing distance estimates through each other and the metric climbs slowly towards infinity before the route is dropped.

Link state routing floods the full topology, so every router computes the paths itself and does not suffer from this problem. Flooding and hierarchical routing are not distance-vector exchanges. Option C is correct. The usual remedies are split horizon, poison reverse and defining a small value as infinity, such as 16 in RIP.

Please log in or register to report this question.

Discuss in Forum
13.

Which of the following statements are true regarding the command ip route 172.16.4.0 255.255.255.0 192.168.4.2?

1.The command is used to establish a static route.

2.The default administrative distance is used.

3.The command is used to configure the default route.

4.The subnet mask for the source address is 255.255.255.0.

Answer: A

Although answer D almost seems right, it is not; the mask is the mask used on the remote network, not the source network. Since there is no number at the end of the static route, it is using the default administrative distance of 1.

Please log in or register to report this question.

Discuss in Forum
14.

Which command displays RIP routing updates?

Answer: B

Correct answer: debug ip rip

debug ip rip shows the updates as they are sent and received, with the networks and metrics in each. show ip route displays the result of those updates rather than the updates themselves, and there is no debug ip route command. As always with debug, it should be enabled briefly on a production router.

Please log in or register to report this question.

Discuss in Forum
15.

Which statement is true regarding classless routing protocols?

1.The use of discontiguous networks is not allowed.

2.The use of variable length subnet masks is permitted.

3.RIPv1 is a classless routing protocol.

4.IGRP supports classless routing within the same autonomous system.

5.RIPv2 supports classless routing.

Answer: C

Correct answer: 2 and 5

A classless protocol carries the subnet mask in its updates, which is what permits variable length subnet masks and discontiguous networks - so statement 2 is correct and statement 1 states the opposite. RIPv2 is classless, so statement 5 is correct. RIPv1 and IGRP are both classful and send no mask, which disposes of statements 3 and 4.

Please log in or register to report this question.

Discuss in Forum
16.

You have the following routing table. Which of the following networks will not be placed in the neighbor routing table?

R    192.168.30.0/24 [120/1] via 192.168.40.1, 00:00:12, Serial0
C    192.168.40.0/24 is directly connected, Serial0
     172.16.0.0/24 is subnetted, 1 subnets
C    172.16.30.0 is directly connected, Loopback0
R    192.168.20.0/24 [120/1] via 192.168.40.1, 00:00:12, Serial0
R    10.0.0.0/8 [120/15] via 192.168.40.1, 00:00:07, Serial0
C    192.168.50.0/24 is directly connected, Ethernet0

Answer: C

Correct answer: 10.0.0.0

The 10.0.0.0/8 route already has a metric of 15, and RIP adds one hop when advertising it onward, giving 16 - which RIP defines as infinity, meaning unreachable. The neighbour therefore discards it. The other entries have metrics of 0 or 1 and will be advertised and installed normally.

Please log in or register to report this question.

Discuss in Forum
17.

What is split horizon?

Answer: A

Correct answer: Information about a route should not be sent back in the direction from which the original update came.

Split horizon is a loop prevention rule: a router does not advertise a route back out of the interface it learned it on, since the neighbour there already has a better path and would otherwise be told about its own route at a worse metric. It is one of several such mechanisms in RIP, alongside route poisoning, hold-down timers and triggered updates.

Please log in or register to report this question.

Discuss in Forum
18.

What command is used to stop RIP routing updates from exiting out an interface but still allow the interface to receive RIP route updates?

Answer: C

Correct answer: Router(config-router)# passive-interface s0

Two things must be right: the command belongs under the routing process rather than on the interface, and the interface is named as its argument. The effect is one-way - the interface stops sending updates while continuing to receive and process them - which suits a link to a stub network or to a device that should not hear the routing protocol.

Please log in or register to report this question.

Discuss in Forum
19.

Two connected routers are configured with RIP routing. What will be the result when a router receives a routing update that contains a higher-cost path to a network already in its routing table?

Answer: B

When a routing update is received by a router, the router first checks the administrative distance (AD) and always chooses the route with the lowest AD. However, if two routes are received and they both have the same AD, then the router will choose the one route with the lowest metrics, or in RIP's case, hop count.

Please log in or register to report this question.

Discuss in Forum
20.

You type debug ip rip on your router console and see that 172.16.10.0 is being advertised to you with a metric of 16. What does this mean?

Answer: C

Correct answer: The route is inaccessible.

RIP counts to infinity at 16, so a metric of 16 is not a distance but a poison: it is how a router announces that a route it once advertised is gone. Since the maximum usable metric is 15 hops, any RIP network wider than that cannot be reached at all - which is one of the protocol’s principal limitations.

Please log in or register to report this question.

Discuss in Forum
Loading…

Topics

Other Subjects

Tags: IP Routing Questions and Answers || IP Routing MCQ Questions and Answers || IP Routing GK Questions and Answers || IP Routing GK MCQ Questions || IP Routing Multiple Choice Questions and Answers || IP Routing GK || GK on IP Routing || Computer Networking Questions and Answers || Computer Networking MCQ Questions and Answers || Computer Networking GK Questions and Answers || GK on Computer Networking

About Us

ExamsRepo

Copyright © 2026 ExamsRepo . All Rights Reserved . With